org.apache.commons.collections4.collection
Class TransformedCollection<E>

java.lang.Object
  extended by org.apache.commons.collections4.collection.AbstractCollectionDecorator<E>
      extended by org.apache.commons.collections4.collection.TransformedCollection<E>
Type Parameters:
E - the type of the elements in the collection
All Implemented Interfaces:
Serializable, Iterable<E>, Collection<E>
Direct Known Subclasses:
TransformedBag, TransformedList, TransformedQueue, TransformedSet

public class TransformedCollection<E>
extends AbstractCollectionDecorator<E>

Decorates another Collection to transform objects that are added.

The add methods are affected by this class. Thus objects must be removed or searched for using their transformed form. For example, if the transformation converts Strings to Integers, you must use the Integer form to remove objects.

This class is Serializable from Commons Collections 3.1.

Since:
3.0
Version:
$Id: TransformedCollection.java 1479401 2013-05-05 21:51:47Z tn $
See Also:
Serialized Form

Field Summary
protected  Transformer<? super E,? extends E> transformer
          The transformer to use
 
Constructor Summary
protected TransformedCollection(Collection<E> coll, Transformer<? super E,? extends E> transformer)
          Constructor that wraps (not copies).
 
Method Summary
 boolean add(E object)
           
 boolean addAll(Collection<? extends E> coll)
           
protected  Collection<E> transform(Collection<? extends E> coll)
          Transforms a collection.
protected  E transform(E object)
          Transforms an object.
static
<E> TransformedCollection<E>
transformedCollection(Collection<E> collection, Transformer<? super E,? extends E> transformer)
          Factory method to create a transforming collection that will transform existing contents of the specified collection.
static
<E> TransformedCollection<E>
transformingCollection(Collection<E> coll, Transformer<? super E,? extends E> transformer)
          Factory method to create a transforming collection.
 
Methods inherited from class org.apache.commons.collections4.collection.AbstractCollectionDecorator
clear, contains, containsAll, decorated, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, setCollection, size, toArray, toArray, toString
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

transformer

protected final Transformer<? super E,? extends E> transformer
The transformer to use

Constructor Detail

TransformedCollection

protected TransformedCollection(Collection<E> coll,
                                Transformer<? super E,? extends E> transformer)
Constructor that wraps (not copies).

If there are any elements already in the collection being decorated, they are NOT transformed.

Parameters:
coll - the collection to decorate, must not be null
transformer - the transformer to use for conversion, must not be null
Throws:
IllegalArgumentException - if collection or transformer is null
Method Detail

transformingCollection

public static <E> TransformedCollection<E> transformingCollection(Collection<E> coll,
                                                                  Transformer<? super E,? extends E> transformer)
Factory method to create a transforming collection.

If there are any elements already in the collection being decorated, they are NOT transformed. Contrast this with transformedCollection(Collection, Transformer).

Type Parameters:
E - the type of the elements in the collection
Parameters:
coll - the collection to decorate, must not be null
transformer - the transformer to use for conversion, must not be null
Returns:
a new transformed collection
Throws:
IllegalArgumentException - if collection or transformer is null
Since:
4.0

transformedCollection

public static <E> TransformedCollection<E> transformedCollection(Collection<E> collection,
                                                                 Transformer<? super E,? extends E> transformer)
Factory method to create a transforming collection that will transform existing contents of the specified collection.

If there are any elements already in the collection being decorated, they will be transformed by this method. Contrast this with transformingCollection(Collection, Transformer).

Type Parameters:
E - the type of the elements in the collection
Parameters:
collection - the collection to decorate, must not be null
transformer - the transformer to use for conversion, must not be null
Returns:
a new transformed Collection
Throws:
IllegalArgumentException - if collection or transformer is null
Since:
4.0

transform

protected E transform(E object)
Transforms an object.

The transformer itself may throw an exception if necessary.

Parameters:
object - the object to transform
Returns:
a transformed object

transform

protected Collection<E> transform(Collection<? extends E> coll)
Transforms a collection.

The transformer itself may throw an exception if necessary.

Parameters:
coll - the collection to transform
Returns:
a transformed object

add

public boolean add(E object)
Specified by:
add in interface Collection<E>
Overrides:
add in class AbstractCollectionDecorator<E>

addAll

public boolean addAll(Collection<? extends E> coll)
Specified by:
addAll in interface Collection<E>
Overrides:
addAll in class AbstractCollectionDecorator<E>


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